Field of the Invention
This disclosure relates generally to a rotor mounting boom for a personal aircraft configured to provide safe operations while achieving robust control and efficient maintenance. In particular, the described embodiments include a rotor mounting boom for an aircraft with vertical takeoff and landing capability. The rotor mounting boom includes a rotor and a controller assembly ventilated by rotor downwash.
Description of Related Art
Taking off and landing vertically, instead of using a runway to develop sufficient velocity on the ground for wings to provide adequate lift, requires an aircraft to provide both vertical and forward thrust. Thrust produced in the vertical direction provides lift to the vehicle; thrust produced horizontally provides forward movement. A vertical takeoff and landing (VTOL) aircraft can produce both vertical and horizontal thrust, and is able to control these forces in a balanced fashion.
The rotary wing aircraft, or helicopter, is one common type of VTOL aircraft. Helicopters have large rotors that provide both vertical and horizontal thrust. For the rotors to perform this dual function across a range of airspeeds, the rotors are typically quite complex. Depending on the vehicle flight condition, the rotor blades must be at different orientation angles around the 360 degrees of azimuth rotation to provide the needed thrust. Therefore, rotors have both collective and cyclic variation of the blade orientation angle. Collective varies the angle of each blade equally, independent of the 360-degree rotation azimuth angle. Cyclic varies the blade angle of attack as a function of the 360-degree rotation azimuth angle. Cyclic control allows the rotor to be tilted in various directions and therefore direct the thrust of the rotor forwards, backwards, left or right. This direction provides control forces to move the helicopter in the horizontal plane and respond to disturbances such as wind gusts.
Helicopter rotors are large and unprotected from hitting nearby obstacles. Additionally, they utilize mechanically complex systems to control both the collective and cyclic blade angles. Such rotors are mechanically complex and require maintenance. The rotors generally rotate at a low speed; this results in heavy transmissions between the rotor and motor. The transmissions, or gearboxes, decrease the vehicle payload potential, as well as vehicle safety. Because of the mechanical complexity across the entire vehicle system, many parts are single points of failure. Because of this lack of redundancy, frequent inspections and maintenance are required to keep the vehicle safe.
Other types of VTOL aircraft have multiple rotors to reduce the single points of failure. However, many vital components, such as motor controllers, are not duplicated, and are thus still single points of failure. These components are not duplicated due to design complexity, weight issues, and maintenance concerns. For example, a motor controller typically needs to be cooled, and including multiple conventional cooling systems on an aircraft increases design complexity and aircraft weight. Additionally, including multiple conventional cooling systems increases the chances that an aircraft will be taken out of service for maintenance.